When software is depricated it is no longer maintained; and when it is no longer maintained cracks happen. We keep our software updated (don't wish to open a can of worms on regressive Windows updates) generally speaking it addresses security issues.
I would not, for exampe, be comfortable using ActiveX.
I might revive a Windows XP VM I have l to perform the update.
If you are using Windows 10, MS Edge should still have the 'Internet Explorer' mode you can select for the target device.
That might work to do the firmware update without the plug-in, though I'm not sure about that.